BACT211: Clinical Bacteriology PDF

# BACT211: CLINICAL BACTERIOLOGY ## **TOPIC:** INTRODUCTION TO DIAGNOSTIC BACTERIOLOGY **2ND SEMESTER | S.Y 2023-2024** **LECTURER:** Ma'am Christy Gonzales ### TOPIC ### SUBTOPIC ### SUB SUBTOPIC ## GENERAL DEFINITIONS - **Microbiology** - a branch of biology which deals with the study of l...

# BACT211: CLINICAL BACTERIOLOGY ## **TOPIC:** INTRODUCTION TO DIAGNOSTIC BACTERIOLOGY **2ND SEMESTER | S.Y 2023-2024** **LECTURER:** Ma'am Christy Gonzales ### TOPIC ### SUBTOPIC ### SUB SUBTOPIC ## GENERAL DEFINITIONS - **Microbiology** - a branch of biology which deals with the study of living organisms that are small to be seen by the naked eye. - We need to use a microscope for us to be able to see/visualize them (microorganisms). - **Medical Microbiology** - a branch of medical science which deals with the study of medically important microorganisms specifically their role in human disease which includes diagnosis, treatment, and prevention of infectious diseases. - Focus of other medical courses: medicine, nursing, physical therapy - **Diagnostic Bacteriology** - a branch of medical microbiology that focuses on the laboratory identification of medically important bacteria by phenotypical and genotypical characterization including antibiotic susceptibility testing. - This is the focus of our program - Diagnostic Microbiology includes bacteriology, mycology, virology, and parasitology. - To be more specific, diagnostic bacteriology, we are dealing with the laboratory identification of medically important bacteria by their molecular characteristics. - Routinely [commonly performed], in the laboratory in the hospital settings, we are identifying the phenotypical [visible trait; seen by the naked eye; morphology, colonial morphology] of the bacteria: - We have two ways of visualizing bacteria: - **Microscopic** [with the aid of microscope; can know its morphology (coccus, spirochetes, etc.), and many more] - **Macroscopic** [we can see this without the use of microscope; colonial morphology (growth of bacteria in the surface of a culture medium)] - Bacteria, like human, have distinct/specific characteristics as well. - In specialized laboratories, they also examine genotypical characteristics [molecular; PCR, DNA composition, nucleic acid composition, etc.] - After identifying the bacteria, the genus and the species, antibiotic testing is also performed to identify what antibiotics/anti-microbial agents that could kill the bacteria. - Each bacterium or each family of bacterium has a unique set of antibiotics that could kill them. - Iba iba ang reaction ng bacteria sa particular antibiotic - There are certain bacteria that couldn't be killed by a particular antibiotic. Thus, the need to identify the antibiotic that could kill it. ## MICROBIOLOGY - Study of microorganisms - Study of certain nonliving entities as well as certain living organisms. - We have two types of microorganisms: - **Acellular infectious agents:** - They do not have the characteristics that are similar to the characteristics of a cell - Instead, they do depend in other cells in terms of reproduction [use cellular organelles of their hosts] - Prions and Viruses [contain nucleic acid and protein] - **Cellular microorganisms:** - Contains cellular organelles (nucleus, ribosomes, ER, etc.) - Has 2 types: - **Prokaryotes** - Lack true nucleus [involves not only the presence of nucleus itself, but should be enclosed in a nuclear membrane] - Has nucleus and genetic material (DNA, chromosome), but lacking nuclear membrane. Thus, we call it a nucleoid region. - Archaea, bacteria - **Eukaryotes:** - Has true nucleus - Nucleus is enclosed in a nuclear membrane - Nucleus contains the genetic material of the cell (DNA, Chromosome) - Algae, Fungi, Protozoa, animal cell, plant cell ## MICROBES - Microbes are said to be ubiquitous. Meaning, they are seen everywhere; virtually everywhere. - **Origin of Bacteria:** - **HUMAN:** - normal flora; non-pathogenic (not capable of causing diseases in normal circumstances, but they have the possibility of transforming from non-pathogenic to pathogenic) - Human → Human - **ANIMALS:** - They are medically important if their bacteria are transmitted to humans - Animal → Human - **ENVIRONMENT:** - Includes soil, water, and air - Reservoir of bacteria - Acquisition of bacteria from the environment - Microbes are subdivided into one of four groups: - **VIRUS:** - Very simple microbes; consisting of nucleic acid, a few proteins, and (in some), a lipid envelope. - Completely dependent on the cells they infect for their survival and replication. - Specific to their host cell [lock-and-key; specific receptor] - HIV → CD4 cell - **BACTERIA:** - With both RNA and DNA; metabolic machinery for self-replication, and a complex cell wall structure (ASEXUAL) - Prokaryotic - simple unicellular organisms - **FUNGI:** - Subdivided into single-celled organisms (yeasts) or multi-celled organisms (molds), with a few medically important members existing in both forms (dimorphic fungi) - Monophormic (exists in uni or multi: yeast or mold; iisa lang ang form) - Dimorphic (has 2 forms: yeasts and molds) - Subdivided into single-celled organisms (protozoa) or multi-celled organisms (worms and bugs) ## DEFINITION OF TERMS RELATED TO INFECTIOUS PROCESS AND DISEASE TRANSMISSION - **Pathogens** - disease causing microorganisms such as bacteria, fungi, protozoans, and viruses, as long as they are capable of causing diseases then they are pathogens. - **TRUE PATHOGENS:** Refers to an organism that will cause disease in a healthy host - **OPPORTUNISTIC PATHOGENS:** Refers to organisms that will cause disease in an immunocompromised host [the immune system is compromised; immunity is low] - **Pathogenicity** - refers to the ability of an organism to cause disease in a host organism. - **Virulence** - refers to the degree of pathogenicity; the power by which a pathogen can cause severe disease - Bawat microorganism have several power in which pathogens can cause disease. - Severity of diseases that a pathogen causes depends on their power. - Ex. Staphylococcus aureus in order for this to cause disease, it has virulence factor [any feature (biochemical/enzymes, genetic, or even the structure the bacteria) which will enable it to cause disease. - Ex. Biochemical - Endotoxin is a biochemical component of Staphylococcus aureus. When it have endotoxin B, this is capable of causing food poisoning. However, when you have Protein A [this is enabling the Staphylococcus aureus to be anti-phagocytic]. Protein A blocks the pathway of phagocytes. - Ex. Staphylococcus aureus is in our blood stream. Then, one of the members of our immune system will try to eliminate it, but if Staphylococcus aureus has Protein A, then it will inhibit or block the antibodies for it to be protected. Thus, Staphylococcus aureus can still cause infection. - Ex. Streptococcus pneumoniae's structure has capsule. Then, it has the same function as Protein A [anti-phagocytic]. Thus, causing infection. - **Not all Staphylococcus Aureus has Endotoxin B. Not all Staphylococcus Aureus has Protein A. Same goes with Streptococcus Pneumoniae in having capsule.** - **Pathogenic Determinants/Virulence Factors** - refers to any genetic, biochemical, or structural features that enable a pathogen to cause disease in a host organism - **Infection** - refers to the entry, invasion, and multiplication of pathogens in or on to the host body system which results to subsequent tissue injury and progress to overt disease. - Bacteria will attach to the host surface. - Ex. The mode of transmission is inhalation for it to go to the lining of our respiratory tract [invade and multiply]. The bacteria will multiply into that host's surface and will cause subsequent tissue injury. That is when manifestation of signs and symptoms occur. - When the bacteria successfully passed our immune system, then that's the time na makakapaginvade siya and multiply. ## TYPES OF INFECTION BASED ON SOURCE OF PATHOGEN - **Infection arising from colonizing flora [also known as indigenous microflora; also known as resident flora, microbiota]** - **Normal flora - non-pathogenic under normal condition; have restricted number in the human system for it not to be pathogenic** - **Normal flora can be pathogenic once an individual is immunocompromised; increase in number [low immunity; the bacteria will increase in terms of their number and when that happens, they will be able to cause disease].** - **It also can be pathogenic once they transfer site [Ex. GIT → urinary tract]. Once it happens, that could cause infection.** - **Infection arising from invading pathogen from the external environment** - **Nakuha ang bacteria from animals or environment** ## TYPES OF INFECTION BASED ON CLINICAL SIGNS AND SYMPTOMS - **ACUTE INFECTION:** Rapid/sudden onset of signs and symptoms which are usually severe to fatal that may lead to death -**CHRONIC INFECTION:** Gradual onset of signs and symptoms that are usually mild to moderate that may progress to long standing infection ## TYPES OF INFECTION BASED ON ETIOLOGIC/CAUSATIVE AGENT - **NOSOCOMIAL INFECTION:** Infection acquired during hospitalization - **Acquired from the hospital: another patient, environment, equipment, etc.** - **ZOONOTIC INFECTION (ZOONOSIS):** Is an animal disease which can spread to humans; animal acquired infection - **SUBCLINICAL/ASYMPTOMATIC/NONAPPARENT:** No obvious appearance of signs and symptoms and the person is unaware of the infection - **CLINICAL/SYMPTOMATIC/APPARENT:** Associated with presence of overt signs and symptoms of the disease. - **Disease:** an altered health state in an infected host - **Infectious disease:** is an illness caused by pathogen that invades body tissues and causes damage -**Communicable disease:** is an infectious disease that is capable of spreading from person to person - **Symptoms:** refers to any subjective evidence of disease. These are usually perception of the patient having the disease such as headache, dizziness, etc. - **Signs:** refers to readily observable evidence of disease. These are usually physical manifestation of the disease such as rashes, bleeding, etc. - **Normal Flora:** bacteria that are in or on different sites of the body that usually do not harm the host unless the host defense is compromised. - **SYNONYMS: Indigenous Flora, Resident Flora, Normal Microbiota** - **Colonization** - refers to the establishment of substantial number of microorganisms usually in the skin or mucosa but there's no penetration of tissues. - Number of normal flora in our body are restricted by our immune system. Once exceeded or increase *in number*, they can now cause disease/s. ### Figure 1: Normal Flora of a Healthy Human Person - Not all anatomic sites in our body have normal flora - **Sterile Site** - without normal flora - **Non-Sterile Site** - with normal flora - Specimens that are obtained in sterile areas [TSF, Peripheral Blood, Body Fluids like synovial fluid] are called **Sterile Specimens**. - Specimens that are obtained in non-sterile areas [GIT: stool, rectal swab] are called **Non-Sterile Specimens** ## EARLIEST KNOWN INFECTIOUS DISEASES - During the ancient times, before the birth of Christ, some believed that diseases are acquired from punishment of the gods, etc. - They believed that once they praise those gods, they will be spared from diseases. - Nowadays, we now know that diseases are caused by particular microorganisms. - **Pestilence & Plague** - Represent the first recorded epidemic - Around 1900 BC, near the end of the Trojan War, the Greek army was decimated by an epidemic of what is thought to have been plague [bubonic plague; caused by the yersinia spp.] - They believed that the epidemic was caused by evil spirits; many have died during those times. - 1500 BC - Ebers Papyrus [Egyptian Medical Papyrus] - Papyrus - documents; - The Egyptian Medical Papyrus contains list of diseases and treatments [during their time] - 1122 BC - Smallpox occurred in China - Epidemics of plague occurred in Rome in 790, 710, and 640 BC and in Greece around 430 BC - There are early accounts of rabies, anthrax, dysentery, smallpox, ergotism, botulism, measles, typhoid fever, typhus fever, diphtheria, and syphilis. - The most common among this is syphilis [caused by treponema pallidum; sexually transmitted infection] - Treponema pallidum – causing syphilis [spirochete: its morphology is spiral] - Syphilis - First appearance in Europe in 1493 - Was carried to Europe by Native Americans who were brought to Portugal by Christopher Columbus. - Neapolitan Disease - French or Spanish Disease - French pox - Spanish, German, Polish, and Turkish pocks - Plague is a zoonotic infection [rodents] - Transmitted to human via rat flee - Yersinia pestis – mode of transmission: bite of a rat flee - Plague has 3 types: - **Bubonic Plague** - swollen lymph glands [bubo]; Black Plague - **Septicemic Plague** - already progressing in our systemic organs [Ex. The infection is scattered to out organs and blood] - **Pulmonary Plague** – respiratory tract infection; acquired via inhalation through respiratory tract. ## PIONEERS IN THE SCIENCE OF MICROBIOLOGY - **ANTON VAN LEEUWENHOEK (1632-1723)** - First person to see live bacteria and protozoa. - "Father of Microbiology" - "Father of Bacteriology" - "Father of Protozoology" - He ground tiny glass lenses, which the mounted in small metal frames, thus creating what today are known as single-lens microscopes or simple microscopes. - not the first one to build a microscope, but was the first one to see an organism under a microscope. - The first one to build a microscope is Descartes. - Quality of his lens of the microscope is not sufficient enough to see microorganisms. - Magnification: x30-x260 - He observed various tiny living creatures, which he called "animalcules” [tiny animals] - First one to made a drawing of bacteria to document; the first drawing was drafted in 1684. ## LOUIS PASTEUR (1822-1895) - Demonstrated that different types of microbes produce different fermentation products. - Can use carbohydrate → acid or alcohol - Disapproves the Theory of spontaneous generation - Life arises from non-living matter [based on Aristotle theory] - John Baptista Van Helmon – 17th century Flemish scientist; had a proposition that "life could arise from rags and wheat kernels which is left in an open container for 3 weeks” → could form a mice [not possible] - He introduced the terms "aerobes" and "anaerobes" - Aerobes require oxygen for growth - Anaerobes do not require oxygen for growth* - Introduced the terminology – Pasteurization - Anti-microbial technique where you heat a liquid in a certain temperature [63-65 degree Celsius for 30 mins or 70-73 degree Celsius for 15 seconds] - Has 2 types: Batch & Flash - Germ theory of disease - Specific microbes cause infectious diseases. - Developed vaccines to prevent chicken cholera, anthrax, and swine erysipelas. ## ROBERT KOCH (1843-1910) - Made many significant contributions to the germ theory of disease - Discovered that *Bacillus anthracis* [spore-producing bacteria] produces spores, capable of resisting adverse conditions - Only 2 is capable of producing bacteria: - *Bacillus spp.* - *Clostridium spp.* - Spores is a virulence factor - It can cause disease when bacillus or clostridium were exposed in extreme conditions [high temp, low pH, high pH, loss of oxygen, high CO2,], it will form a spore as a form of their survival. They are still capable of causing infection - Developed methods of fixing, staining [methylene blue: the one used in *M. tuberculosis* (heat is applied)], and photographing bacteria, methods of cultivating bacteria on solid media - Methylene blue [1877] - Acid-fast staining - Used methylene blue then employed heat - *M. Tuberculosis* is not an ordinary bacterium [cell wall is hard to penetrate using ordinary stain] - Methylene blue alone cannot penetrate the cell wall of *M. Tuberculosis* - In 1822, Robert Koch found a way to penetrate the waxy cell wall of *M. Tuberculosis* by applying heat. [methylene blue + heat = fast stain] - Discovered the bacterium *Mycobacterium tuberculosis* that causes tuberculosis and the bacterium *Vibrio cholerae* that causes cholera. ## KOCH'S POSTULATES ### Figure 1-10. Koch's Postulates: proof of the germ theory of disease - It is also important to keep in mind that not all diseases are caused by microbes. - All infectious diseases and microbial intoxications are caused by microbes. ## THE DISCOVERY OF SPORES AND STERILIZATION - **JOHN TYNDALL** - Provided the initial evidence that some of the microbes in dust and air have very high heat resistance and that particularly vigorous treatment is required to destroy them - Hindi lahat ng microorganism could not be killed by very high temperature. Instead, they can be killed by vigorous treatment [tyndallization] - You use repeated heating and resting method [consecutive heating then resting then heat then rest, and repeat the process until the microorganism dies] - Most bacteria requires 100 degree Celsius to be killed, some requires higher than that. ## THE DEVELOPMENT OF ASEPTIC TECHNIQUES - **DR. OLIVER WENDELL HOLMES** - Observed that mothers who gave birth at home experienced fewer infections than did mothers who gave birth in the hospital. - Mas maraming makukuhang infection sa hospital kaysa sa bahay - **DR. IGNAZ SEMMELWEIS** - Showed quite clearly that women became infected in the maternity ward after examinations by physicians coming directly from the autopsy rooms - Infection of newly mothers after giving birth: childbed fever - Father of Handwashing - **JOSEPH LISTER** - First to introduce aseptic techniques aimed at reducing microbes in a medical setting and preventing wound infections. ## FERDINAND COHN - Clarified the reason that heat would sometimes fail to completely eliminate all microorganisms - “STERILE” was established - Sterile - completely free of all life forms (including spores) and virus particles. - Staining of histological specimen - Histologic specimens: tissue specimens [carmine and hematoxylin (vegetable dyes)] - Basal medium - Culture media have basal medium in to which factors can be added to non-fastidious bacteria - Two types of bacteria in terms of requirement: fastidious [require additional or special nutrient] vs. non-fastidious [standard requirement for growth] ## THE DEVELOPMENT OF ASEPTIC TECHNIQUES - **DR. OLIVER WENDELL HOLMES** - Observed that mothers who gave birth at home experienced fewer infections than did mothers who gave birth in the hospital. - Mas maraming makukuhang infection sa hospital kaysa sa bahay - **DR. IGNAZ SEMMELWEIS** - Showed quite clearly that women became infected in the maternity ward after examinations by physicians coming directly from the autopsy rooms - Infection of newly mothers after giving birth: childbed fever - Father of Handwashing - **JOSEPH LISTER** - First to introduce aseptic techniques aimed at reducing microbes in a medical setting and preventing wound infections. ## ADDITIONAL: - **Friedrich Loeffler in 1890** - He discovered or demonstrated the presence of bacterial flagella [motile, non-motile]. - **Baijerinck in 1898** – enrichment medium - **Chamberland in 1884** - discovered the autoclave - **Mcintosh & Fildes** – anaerobic jar ## CAREERS IN MICROBIOLOGY - **BACTERIOLOGIST** - the study of the structure, functions, and activities of bacteria - **PHYCOLOGISTS (OR ALGOLOGISTS)** - Scientists specializing in the field of phycology (or algology) study the various types of algae ## PROTOZOOLOGIST - Explore the area of protozoology – the study of protozoa and their activities. ## MYCOLOGIST - Those who specialize in the study of fungi, or mycology ## VIROLOGISTS AND CELL BIOLOGISTS - May become genetic engineers who transfer genetic material (deoxyribonucleic acid or DNA) from one cell type to another - Virologists also study prions and viroids, acellular infectious agents that are even smaller than viruses ## FOCUS OF DIAGNOSTIC BACTERIOLOGY FOR MEDTECH - When identifying the bacteria or microorganism present, we need to check the clinical diagnosis of the patient [suspected clinical diagnosis] - Then, we need to correlate it to the bacteria we've seen and then, release the form. - Once we've identified the bacteria, we need to identify what specific antibiotic needed to kill the bacteria. ## NAMING, CLASSIFYING, AND IDENTIFYING MICROORGANISMS - **Taxonomy** - the science of classifying living things - In Greek, taxonomy came from “taxes” and “nomos”. - “taxes” - arrangement - “nomos” - law - Involves 3 structured and interrelated category that include: - **Nomenclature** - is the assignment of scientific names to the various taxonomic categories and individual organisms. [based on international rulings] - ☐ 1 label for a specific microorganism [universal] - **Classification** – attempts the orderly arrangement of organisms into a hierarchy of taxa (categories). - Taxa - plural; Taxon - singular. - Classified based on their similarities or relationships; closely related. - **Identification** - process of discovering and recording the traits or organisms so that they may be recognized or named and placed in an overall taxonomic scheme. ## CLASSIFICATION - **CARL VON LINNÉ** (ALSO KNOWN AS LINNAEUS; 1701-1778) - A Swedish botanist - Laid down the basic rules for classification and established taxonomic categories, or taxa. ## HOW ANIMALS ARE CLASSIFIED - **Species can still be subdivided by:** - sub-specie [based on differences of phenotypic characteristics] - serovarieties [serologic differences; antigen, antibody composition] - biovarieties [biochemical test result] ## ROBERT WHITTAKER - Whittaker's tree - based on structural similarities and differences, such as prokaryotic and eukaryotic cellular organization, and the way these organisms obtained their nutrition - **Monera → Protists → Plants → Fungi → Animals** ## CARL R. WOESE - Devised a Three-Domain System of Classification - There are two domains of procaryotes (Archaea and Bacteria) and one domain (Eucarya or Eukarya), which includes all eucaryotic organisms. ### Figure 1.14 The tree of life: A phylogenetic system. A system for representing the origins of cell lines and major taxonomic groups. There are three distinct cell lines placed in superkingdoms called domains. The first primitive cells, were ancestors of both lines of "prokaryotes" (Domains Bacteria and Archaea), and the Archaea emerged from the same cell line as eukaryotes (Domain Eukarya). ## NOMENCLATURE - **International Code of Nomenclature of Bacteria (ICNB) or the Bacteriological Code (BC)** - Provides the accepted labels by which organisms are universally recognized. - **Binomial system of nomenclature** - Every organism is assigned a genus and a species of Latin or Greek derivation. - Sometimes, it includes the subdivision of specie, but normally, 2 lang: genus and specie - Each organism has a scientific "label" consisting of two parts: - **GENUS** - the first letter is always capitalized - **SPECIES** - first letter is always lower case - Printed in italics or underlined in script. ## GUIDELINES - The first letter of the family name (similar to a human "clan") is capitalized and has a suffix – aceae - Hindi na need na italicized/underlined - The first letter of the genus is capitalized followed by the species in lowercase; both the genus and species should be italicized in print or should be underlined when written in script. ## IDENTIFICATION - **GENOTYPIC CHARACTERISTICS** - Relate to an organism's genetic makeup, including the nature of the organism's genes and constituent nucleic acids. - **PHENOTYPIC CHARACTERISTICS** - Are based on features beyond the genetic level and include both readily observable characteristics and characteristics that may require extensive analytic procedures to be detected. - **Commonly, the genus is abbreviated with the first letter (capitalized) of the genus followed by a period and the species.** To avoid confusion, the first two letters of the first syllable are used when two or more genera begin with the same first letter. - *S. aureus* - Maraming genus na nagsisimula sa S, so we avoid abbreviation to avoid confusion as well - WE WILL NOT USE ABBREVIATION [IN EXAMINATIONS OR QUIZZES] - **The genus followed by the word species may be used to denote the entire genus as a whole.** The species are abbreviated as "sp." (singular) or "spp." (plural) when the species is not specified. - Lastly, when bacteria are referred to as a group, their names are neither capitalized nor underlined. - Kapag ang tinutukoy ay yung buong genera [as a group; as is] ## TABLE 1-1 Comparison of Prokaryotic and Eukaryotic Cell Organization | Characteristic | Prokaryote | Eukaryote | |---|---|---| | Typical size | 0.4-2 µm in diameter <br> 0.5-5 µm in length | 10-100 µm in diameter <br> >10 µm in length | | Nucleus | No nuclear membrane, nucleoid region of the cytosol | Classic membrane-bound nucleus | | Genome | In the nucleoid, at the mesosome | In the nucleus | | Chromosomal DNA | Circular, complexed with RNA | Linear; complexed with basic histones and other proteins | | Genome : extrachromosomal circular DNA | Plasmids, small circular molecule of DNA containing accessory information; most commonly found in gram-negative bacteria; each carries genes for its own replication; can confer resistance to antibiotics | In mitochondria and chloroplasts | | Reproduction | Asexual (binary fission) | Sexual and asexual | | | | | | Membrane-bound organelles | Absent | All | | Golgi bodies | Absent in all | Present in some | | Lysosomes | Absent in all | Present in some; contain hydrolytic enzymes | | Endoplasmic reticulum | Absent in all | Present in all; lipid synthesis, transport | | Mitochondria | Absent in all | Present in most | | Nucleus | Absent in all | Present in all | | Chloroplasts for photosynthesis | Absent in all | Present in algae and plants | | Ribosomes: site of protein synthesis (nonmembranous) | Present in all | Present in all | | Sterols in cytoplasmic membrane | Absent in most except in Mycoplasma spp. | Present; some animal cells | | Plasma membrane | Lacks carbohydrates | Also contains glycolipids and glycoproteins | | Cell wall, if present | Peptidoglycan in most bacteria | Cellulose, phenolic polymers, lignin (plants), chitin (fungi), other glycans (algae) | | Glycocaylx | Present as an organized capsule or unorganized slime layer | Present; see description of flagella | | Cilia | Absent | Present; | | Flagella, if present | Simple flagella, composed of polymers of flagellin; movement by rotary action at the base, spirochetes have MTs | Complex cilia or flagella; composed of MTs and polymers of tubulin with dynein connecting MTs; movement by coordinated sliding microtubules | | Pili and fimbriae | Present | Absent | - To locate the nucleoid region, it is usually attached to the mesosomes that can be found at the plasma membrane of the cell - In terms of the cellular organelle, ribosomes are the only cellular organelle present in both prokaryotes and eukaryotes - In reproduction, bacteria: binary fission [asexual] - Peptidoglycan [can be seen in the cell wall of prokaryote] ### Figure 3-6. A typical procaryotic cell